What is this?

When U.S. and European airlines quickly cancelled flights to Israel Tuesday, they showed both a skittishness and a new sense of urgency in dealing with global trouble spots following last week’s downing of a passenger plane over Ukraine.

Delta Air Lines turned around one of its jets midflight and indefinitely cancelled all future flights between the U.S. and Israel after a rocket fired from the Gaza Strip landed near Tel Aviv’s Ben-Gurion Airport. Other U.S. airlines quickly took similar action, and counterparts in Europe and Canada followed within hours, despite protests from the Israeli government. Israeli airline El Al maintained its regular flight schedule.

The airlines were out ahead of aviation regulators in stopping service. The Federal Aviation Administration imposed a 24-hour ban on flights to Israel after the U.S. airlines acted. Germany’s Lufthansa, Italian airline Alitalia and Air France all acted before the European Aviation Safety Agency issued an advisory.

How long the cessation of flights will last is unclear. U.S. airlines now must wait for the FAA, which said it will provide updated guidance by midday Wednesday.

Korean Air Lines Co. said on Friday that it was suspending its flights between Incheon International Airport near Seoul and Tel Aviv until at least Thursday, citing tensions between Israel and Palestine.

Aviation and legal experts said that airlines are now taking risk assessment into their own hands, both for the safety of passengers and to avoid claims of negligence, following last week’s Malaysia Airlines disaster.

“Most airlines have security departments that try to evaluate those sorts of risk,” said William Waldock, a professor of safety science at Embry-Riddle Aeronautical University. “Some do it better than others, but I would expect that everyone is on a very heightened sense of alert right now.”

Richard Aboulafia, an analyst with the Teal Group, said airlines might be more proactive about avoiding hot spots, although he noted that there are very few areas where non-government militaries have weapons sophisticated enough to shoot down a plane.

Western governments have accused pro-Russian separatists in Ukraine of shooting down Malaysia Airlines Flight 17 with a surface-to-air missile while it was flying at 33,000 feet. Some experts have second-guessed the airline’s decision to fly over the area. But Malaysian officials have countered that the plane’s path from Amsterdam to Kuala Lumpur was approved by international regulators.

The Israel government felt the airlines overreacted Tuesday. The Transportation Ministry called on the companies to reverse their decision, insisting Ben-Gurion Airport is safe and completely guarded and saying there is no reason to “hand terror a prize,” by halting the flights.

Former New York Mayor Michael Bloomberg strongly urged the FAA to “reverse course” and permit U.S. airlines to fly to Israel.

Bloomberg released a statement saying he is flying on El Al to Tel Aviv on Tuesday night to “show solidarity with the Israeli people and to demonstrate that it is safe to fly in and out of Israel.”

“The U.S. flight restrictions are a mistake that hands Hamas an underserved victory and should be lifted immediately,” Bloomberg said.

WATCH: Last week’s disaster over Ukraine and a perceived increase in risk to flights flying to Israel’s Ben Gurion International Airport, due to rocket fire from Gaza, have prompted airlines to reroute or cancel flights.

Palestinian militants have fired more than 2,000 rockets toward Israel, and several heading toward the area of the airport have been intercepted by Israel’s Iron Dome defence system, but police spokeswoman Luba Samri said Tuesday’s landing was the closest to the airport since fighting began on July 8.

While Hamas rockets aren’t as sophisticated as the guided missile that the U.S. and others contend hit the Malaysian jet, they can cause massive damage if they hit an aircraft. For instance, unguided mortar fire in Tripoli from a militia batting to control its international airport destroyed a $113 million Airbus A330 used by Libya’s state-owned Afriqiyah Airways over the weekend.

Last year, an average of 1,044 passengers flew each way on the four daily flights between the U.S. and Israel on American carriers, according to the Bureau of Transportation Statistics.

Jack Ram, 50, of Tel Aviv, who was in New York visiting friends, said threats of violence and disruptions while travelling were nothing new for Israelis. He prayed Tuesday before entering the departure area at Newark, New Jersey, for his El Al flight to Israel.

“We’re used to it. That’s how we live for the last 30 . 3,000 years actually,” Ram said.

Jonathan Reiter, a prominent New York aviation-accident attorney, said flying into an airport after a near-miss by a rocket could be used to show that the airline was negligent. That explains why the airlines are suspending service to Israel.

“I’m sure it is human concern as well,” Reiter said, “but I think (the airlines) feel it is wise to err on the side of caution because it is their burden to prove they are doing everything possible to avoid injuries and deaths.”